As title really; what is the best ratio. I live in plymouth which has lots of short sharp hills followed by similar descents. I need it easy enough to get up but still maintain a decent speed on the flats. It’s primarily for commuting to work which has some killer short climbs followed by long periods of semi-flatness.

So what do you run?

Get a 32t or 34t chain ring and a bunch of sprockets I guess. It is pretty hard to answer that for you.

The gear calculator is pretty helpful to see what kind of speeds you are looking at for a given gear ratio and cadence.

I run a spinny 32:20 for mid length, steep climbs we have here around Bath and my seriously poor fitness for whatever that is worth 🙂

I use 32×18 on my 29er that I only use offroad and 40×16 for my 29er with slicks that I use for commuting along fairly flat fire roads and towpaths. I would probably suggest 36×18 as a good do-everything ratio if you’re riding on a mix of surfaces.

If you’re only going of road though, 32×18 is, St least for me, perfick.

32:17 currently running and works for me in the Surrey hills 😉

Both mine are 2:1 26″ equivalent (52 gear inches), i.e. 36:20 on 29er

I stuck to 36T so that, if I chose, I could revert to using the Rohloff (and need 36:16 on that)

However, I have for both my SS gone oval 36T. ratio is still fine, extra bit of help from the ovalising is great for here on the Malverns.

Don’t listen to the willy waving 🙂 Ok do, the 32:20 I use for example would be massively tedious for any period of extended flat riding, especially commuting. 32:18 is probably a fair start is its mostly off road as others have suggested. Another crazy idea… can you ride a geared bike in one of the suggested gears and see how you get on?

The “usual” advice is 2:1 on a 26er, say 32:16, but 32:18 for a 29er. That’s a starting point and then it depends on your terrain, fitness, are you a masher or a spinner?

I used to run 33:17 on a 26er, but my back just can’t take it any more. I’ve been faffing with ratios, 32: 16,17,18,19. And can’t get a happy set up. Too spiny, too tough.

I just need to pick one and get on with it.

Someone once said that “single speeding is pick a gear, it will never be he right one”.

Standard rule of thumb was 2:1 for 26″ and 2:1 plus 2t for 29 to allow for addtional wheel diameter so 32:18 is a good starting point. If using an elliptical front ring go 2t up so 34:18 should be tippy top. As with all ss it depends if you are a mosher or master of spinjitsu and where you ride most.

I used to run 32:18 pretty much everywhere on my 29er and it seemed pretty good.

Then one day I discovered the derailleur. Seriously, try it, you might like it. 😀

My commute involve short sharp climbs followed by long flats. The worst combo I guess! Currently run 2x but am fed up of constantly repairing/indexing/fixing the gears. I go through deep mud and some days it is so bad it won’t change gear at all! Everything is knackered and needs replacing so figured ss might be a good option… thanks 32/18 sounds like a goer…

I run 34(oval) x 18 in the winter and flip to a 16 in the summer. Although I’m regretting it this year!

I also use the 16 when I’m touring with slicks on. Works fine and give me a good 14mph average with panniers etc.

Depends what you’re happy with – if you’re not sure, maybe get a 34 and a couple of different sprockets (use cogs from an old cassette to get an idea, assuming you’ve a splined freehub)

I use 34×17 year round, I live in Scotland and race XC on it. Anything smaller is too spinny too much of the time.

32:18 works for me on the short, sharp, hilly Isle of Wight.

Used to run a 34 oval ring up front but the chain skipped off just once too often with it.

Remember it’s not really a singlespeed.

You’ve got the sitting down gear, the standing up gear, the bent double over the bars gear and the getting off and walking gear.

34×16 on the Isle of Wight too, but putting on an 18 asap 😉

As others have said only you can work out what is best for you and your terrain.

It is clearly a compromise with single speed so for me it is just getting the right gear for the majority of the rides I do. I use a gear as high as I can while keeping ability to gets up all the climbs, ride up all the slow single track etc,.
I just forget about pedalling downhill as that is never going to happen and I can spin very well after many years so can still maintain a decent speed on flat.

For me that worked out at the very commonly used 52″ gearing (32/16*26, 32/18*29). I usually go up to 55″ in the summer but haven’t bother this year as it makes the slower single track harder.

I liked 33/19 but I cant’t find a direct mount 33 to use so am on 32/18.Might try 30/17 because reasons.
Will probably dig out the 20 for Kielder and the Marathon champs.
Also to appease the geary muppets and ladies ‘there is no best option….only the least worst’

I use 30:16 up here in North Wales. This has taken me round the beast at CyB, Llandegla black, towpaths, Isle of Man and has felt good. A little spinny sometimes on flat hardpack, but overall, happy with it.

42/17 worked great on my old Tricross Singlecross, for a ~5 mile commute each way with a ~1 mile ~6% gradient hill near home. But it is/was a very light bike for its price in 2010, <1Kg heavier than my Felt F5C.

On a MTB 29er, I’d probably go something like 32/20.

I used to ride 32:18 around Cannock Chase. It’s good to get you going and build strength/fitness. 32:17 seems to be where it’s at for me at the moment. Dropping one tooth doesn’t seem like much but it feels a lot harder on the climbs and has made me faster on the flat.

I used 32:20 on my 29er in Bristol (surely not dissimilar to Bath).

32 X 18 in Bristol on the SS, 32 X 16 on the fixed gear 29er….